Comparison with GRASS interface via qgisprocess

[Robinlovelace]

Just capturing useful discussion during the FOSS4G workshop on rgrass:

• It would be good to define and document how qgisprocess compares with this package for benefit of users and developers
• qgisprocess has the advantage that it allows access to ALL QGIS plugin algorithms, around 1k+ with the OSGeo4W install
• qgisprocess has the disadvantages that it's not yet on CRAN and cannot access all functionality in GRASS (those from plugins?)
• A division of labour, assuming qgisprocess gets on CRAN, could be documenting that basic r.* functions can be called from qgisprocess but that rgrass is needed for more advanced things

Relevant issue: r-spatial/qgisprocess#46 may be worth tagging people on this to link things together.